'71 Rear Electrical Issues

[Bears63]

Truck in question is a '71 Cheyenne. The problems are thus:

1) Headlights on - nothing works on the back. No markers, tail lights, nothing.
2) Brakes - Everything out back will light up dimly. Tail lights, markers, all of it. This happens with lights on or off.
3) Blinkers - Either direction will cause everything to flash dimly. Tail lights, markers, all of it. This happens with lights on or off.
4) The left tail light bulb gets burned up quickly. It takes very little usage before it's no good.

In troubleshooting I tested at the connector where the tail light harness plugs into the main harness. Everything tested properly on the main harness. I went to start looking at the tail light harness and it was such a rats nest that I just yanked all of the wiring and replaced most of it. The pigtails for the tail lights looked okay so I reused them. When I was done everything worked properly, which was just last night. All turn signals, marker lights, tail lights, and brake lights worked fine. After driving the truck around town today it's now back to the same crap. Does this sound like grounding issues? It sure seems like it to me. The lights did all work fine just a month ago, so it is perplexing and I am not sure what else to look at at this point.

[cdowns]

lean how the system is grounded and things tend to work better with a ground path from the light bulbto the battery

[Bears63]

Problem solved. I ran two ground straps, one on each side, from the bed to the frame and everything works just fine.

[Reed's72]

This site is great, This same problem came up a couple weeks ago but I hadn't looked at it because the truck was down waiting for a new carb. A good friend of mine was over last night helping me install the new carb after that we tested all the lights just like Bear, as he was leaving he told me I had to post the problem but before I could he found this post, needless to say a set of grounds fixed the problem. Thanks